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  #1  
05-18-2004, 03:55 PM
Hydeus Hydeus is offline
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I've noticed that newer versions of ffvfw (ffdshow encoder now, but not for long ) have settable MPEG2 DC precision to 8, 9, 10, 11 bits. It does affect quality a bit (higher value = higher quality + smaller filesize).
However I can't find this feature in mencoder, and all encodings are made at precision 8.
Does anybody know if its possible to set other than 8 DC recision
And secondary is 11bit encoded file still full DVD compliant (maybe stupid question )
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05-18-2004, 04:48 PM
Dialhot Dialhot is offline
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Quote:
Originally Posted by Hydeus
higher value = higher quality + smaller filesize
That's a little more complicated than that, as always in video editing.

Quote:
And secondary is 11bit encoded file still full DVD compliant (maybe stupid question )
The only prototype level allowed on DVD is MP@ML. This prototype allows only DC up to 10. 11 is available only in higher prototype (HP@ML and Y422@MP)

The question wasn't so stupid
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05-18-2004, 04:59 PM
Hydeus Hydeus is offline
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Thx Phil.
Quote:
Originally Posted by Dialhot
Quote:
Originally Posted by Hydeus
higher value = higher quality + smaller filesize
That's a little more complicated than that, as always in video editing.
I've made some tests and that was my results. But of course there's always differend end for differend story
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05-18-2004, 05:01 PM
Prodater64 Prodater64 is offline
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Quote:
Originally Posted by Hydeus
...
However I can't find this feature in mencoder, and all encodings are made at precision 8.
Does anybody know if its possible to set other than 8 DC recision
First who was looking for that is Kwag (as I know it). Later many others try to find out something in this sense. But it seems that no way.
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05-18-2004, 05:06 PM
Dialhot Dialhot is offline
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Quote:
Originally Posted by Hydeus
I've made some tests and that was my results. But of course there's always differend end for differend story
The complication is not only in the encoder, but also in the decoder.
A lot of MPEG2 decoding chipset doesn't support DC=11. They decode anything with a 10 bits precision. That means that you have clipping/rounding in the values.

It's like having a picture in 32bits colors but a video card that only displays 24bits

Where are the benefits ?
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05-18-2004, 05:14 PM
Hydeus Hydeus is offline
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Quote:
Originally Posted by Dialhot
The complication is not only in the encoder, but also in the decoder.
A lot of MPEG2 decoding chipset doesn't support DC=11. They decode anything with a 10 bits precision. That means that you have clipping/rounding in the values.

It's like having a picture in 32bits colors but a video card that only displays 24bits

Where are the benefits ?
Aha. Many thx Phil, for pointing this. I assume that if ffdshow can encode in 11 bits then it also can decode in 11 bits. AFAIK mpeg1/2 decoder is still buggy but Milan is workin on this.
I understand that in terms of standalones, it is beter (safer) to encode in 10 bits, to avoid "flowers"
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05-18-2004, 05:17 PM
Dialhot Dialhot is offline
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Quote:
Originally Posted by Hydeus
I understand that in terms of standalones, it is beter (safer) to encode in 10 bits, to avoid "flowers"
In a general way of speaking : Yes. Even if good surprise is always possible.
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